Vapor condenser for dishwasher vent system



June 11, 1968 H. c. WILLIAMSON VAPOR CONDENSER FOR DISHWASHER VENT SYSTEM Filed March 8, 1966 FIG. 3.

FIG. I.

INVENTOR Hugh C. Williamson ZZQMCM ATTORNEY United States Patent 3,387,382 VAPOR CONDENSER FOR DISHWASHER VENT SYSTEM Hugh C. Williamson, Columbus, Ohio, assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Mar. 8, 1966, Ser. No. 532,634 2 Claims. (Cl. 34-72) ABSTRACT OF THE DISCLOSURE Vapor condenser apparatus comprising a condensing plate shielded from the dishwater tub by thermal insulating material, the plate and thermal insulating material being located at the upper end of a housing serving both as a water fill housing and as a venting housing.

This invention relates to a vapor condenser arrangement for a domestic dishwasher vent system.

In my U.S. patent application Ser. No. 514,641, entitled, Single Vent System for Dishwasher, I disclose a vent system for a dishwasher in which one of the washing chamber sidewalls carries a water fill housing on its exterior face, the fill housing defining a vent passage for water-laden air leaving the washing chamber during the drying cycle. Slot means provided in the chamber sidewall place the washing chamber in communication with the water fill housing interior and these slot means serve :as both the inlet and outlet for venting air during the drying cycle. Since the water fill housing is typically located in a confined space surrounded by kitchen cabinets and building structure in the undercounter version of such a dishwasher, the entirety of the moist venting air is discharged into this cabinet space. To the extent possible therefore, it is desirable that as much water be removed from the air before it finally escapes into the cabinet space.

Thus, an object of this invention is the provision of means for condensing part of the water vapor before it leaves the vent passage structure, and the provision of means for carrying the water back to the washing chamber.

In accordance with the invention the outlet of the fill housing is provided 'with an extension which comprises vapor condensing means, and which essentially includes condensing plate means and means for shielding the c0ndensing plate from heat emitted by the washing chamber sidewall. As the vapor-laden air passes upwardly out of the fill housing, the vapor condenses on the relatively cool condensing plate means and drains back into the washing chamber through the water fill housing.

The invention will be further described in connection with the accompanying drawings showing a dishwashing machine incorporating the principles of the invention by way of example, and wherein:

FIGURE 1 is a side view of an undercounter type dishwashing machine to which the invention is applied, this view omitting some of the structural details which do not bear on the inventive concept;

FIG. 2 is a fragmentary isometric view of a side wall of the washing chamber carrying the water fill housing and condensing means; and

FIG. 3 is a vertical sectional view corresponding to one taken along the line III-III of FIG. 1.

The dishwasher in FIG. 1 is shown mounted in a cavity below the counter top and has the conventional overall rectangular box-shape defined by a top wall 12, opposite sidewalls 14, rear wall 16, front wall 18 including an access door portion 20, and a bottom wall 22. The various walls are formed with appropriate embossments for strength and other purposes, but such details of configuration are not illustrated except for the bottom wall sump 24 to which draining water gravi'tates for recirculation or to be discharged to the drain.

The interior washing chamber of the machine, generally designed 26, is provided with the usual openwork racks (not shown) for supporting the articles to be washed. These articles may be inserted from the front of the machine when the access door 20 is opened. A pump motor 28, diagrammatically shown in FIG. 1, furnishes power to draw washing and rinsing water from the sump 24 and forcibly hurl it about the washing chamber through means of one or more revolving spray arms (not shown) and to force the used water out to a drain point at the proper time of the cycle. The chamber also contains a resistance heating element 32 adjacent the bottom wall to provide supplemental heat to the wash and rinse water, and to provide the heat for drying the dishes during the drying cycle.

The wash and rinse water is supplied to the washing chamber through a solenoid-valve controlled pipe 34 which empties into a fill housing 36- mounted against the outer face of one of the side walls 14-. This fill housing is in the form of a generally rectangular box formed by outer wall 40, end walls 42 and 44, and horizontal bottom wall 46. The inner edges of the end walls and the bottom wall abut the sidewall 14 of the washing chamber in sealed relation to form the upwardly-open pocket or chamber into which water for washing and rinsing is supplied, and from which it flows into the washing chamber through a horizontally extending series of slots 38 (MG. 3). As shown, the fill housing has substantial length in a front-to-rear direction along the wall 14, but is of relatively limited height and thickness.

The fill housing 3.6, in addition to serving as a plenum through which wash and rinse water are supplied, forms a part of the vent system. As such, it provides a vertically-extending passage in communication at its lower end with the interior of the washing chamber through the slot means 38, and is open at its top end for conveying the venting air into the vapor condensing section generally designated 48 and mounted on top of the fill housing.

As shown in FIG. 3, the fill housing includes a deflector bafile member 50 which extends from front to rear between the opposite end walls of the fill housing, and which cooperates with the outside wall 40 of the fill housing to carry a highly porous open-cell pad 52 which serves as a water and air separator as explained in another of my copending U.S. patent applications, Serial No. 514,640, entitled Dishwashing Machine and Porous Pad.

While the vapor condensing means 48 may take various forms depending upon the environment in which it is applied, it essentially comprises condensing plate means 54 and shielding means 56. The condensing plate means 54 may simply be a sheet of aluminum, or some other good thermally conductive material which does not deteriorate when moisture condenses thereon. The shielding means is preferably formed of a material having good thermal insulating qualities. Certain plastic materials such as beaded styrene which may be easily molded are quite satisfactory.

The shielding means 56 may be molded as shown in r16. 2 in the form of a shallow channel in which the terminal ends of the legs are provided with slots 58 in facing relation to receive the front and rear edges of the condensing plate 54. By supporting the condensing plate in this manner, any problem of heat from the washing chamber sidewall 14 being conducted through the supporting means to the condenser plate is avoided. Since the fill housing 36 is also preferably of a molded plastic, the condensing plate 54 is not connected directly to any part which is a good conductor of heat from the washing chamber. The shield 56 of course also insulates against the radiation of heat from the washing chamber to the condensing plate 54.

In operation, when the washing machine is in a drying cycle, hot moisture-laden air is vented through the slots 38 and upwardly through the fill housing 36. A good deal of the moisture is of course captured by the air and water separating pad 52, while part of the moisture in vapor form passes through the pad and upwardly out of the water fill housing into the condensing section. The condensing plate 54, which generally has a temperature corresponding to the temperature in the cabinet space around the dishwasher, will have a substantial part of the vapor condensed out on its inner surface and this condensed vapor will then flow down the inside face of the plate and back into the washing chamber through the fill housing.

It is not necessary that all of the water vapor which exits from the machine be captured by the condensing means, since a certain amount of this water may escape into the cabinet space without adverse effects to the building structure and cabinet structure. However, an arrangement according to the invention materially reduces the amount of vapor which escapes into the cabinet space.

It will be appreciated that an arrangement according to the invention may take various forms other than the specific form shown. For example, the condensing plate means may well take the form of individual blades extending part of the way across the air flow passage, or the plate may be corrugated, or take other forms. Also, the water fill housing and the vapor condensing section may be constructed as a unitary assembly rather than the two separate assemblies shown as an example.

Having described my invention, I claim: 1. In a dishwashing machine:

5 a washing chamber having venting outlet means in a vertical wall of said chamber;

means including an upwardly-open water fill housing forming an upwardly-directed passage having its lower end in communication with said venting outlet means on the exterior of said wall; and

vapor condensing means connected to said passage including condensing plate means comprising a metallic member spaced apart from said insulating member and shielding means comprising a thermal insulating member covering a portion of the exterior face of said chamber wall above said housing upper end for shielding said condensing plate means from heat emitted by said chamber, said insulating member and said metallic member providing a continuation of said upwardly-directed passage.

2. In a dishwasher according to claim 1:

said insulating member comprises a three sided member including means for receiving said metallic member to form a fourth side.

References Cited UNITED STATES PATENTS 1/1879 Wickes 34-75 3/1962 Berger et al. 34231 H. B. RAMEY, Assistant Examiner. 

